Scissors jack



Aug. 30, 1955 D. A. GALONSKA SCISSORS JACK 2 Sheets-Sheet 1 Filed June 8, 1949 Emacntor awy /azzia Aug. 30, 1955 D. A. GALONSKA 2,716,537

SCISSORS JACK Filed June 8, 1949 2 Sheets-Sheet 2 Zhwentor n M r v attorney;

United States Patent SCISSORS JACK David A. Galonska, Saginaw, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application June 8, 1949, Serial No. 97,895

13 Claims. (Cl. 254-122) The invention relates to jacks and particularly to an improved ball nut scissors jack with a combined handle and guide member.

The scissors type jack consists of two pressure pads connected by a crossed parallelogram linkage which will maintain the pads in parallel relation. The opposed sides are connected together by a screw and ball nut. The jack is elevated when the screw is rotated to move the ball nut toward the screw head. The ball nut has a one-way ball circulating passage formed by a substantially radial transfer passage at the screw, to provide a friction brake during reverse rotation of the screw. Thus the load will not lower the jack due to the weight of the vehicle but must be cranked down. The jack is handled and positioned by the collapsible handle and guide, which is designed so that it engages the side of the vehicle when the jack pad is under a suitable portion of the vehicle for lifting.

An object of the invention is to provide a scissors jack with a foldable wire handle and guide for positioning the jack so that the jack lifting pad engages a suitable lifting portion of the vehicle when the end of the guide engages the side of the vehicle.

Another object of the invention is to provide in a linkage jack having a handle and guide member pivotally mounted on the jack so that the jack lifting pad engages a suitable lifting portion on the vehicle when the end of the guide engages the side of the vehicle;

stop members which will limit the movement of the handle and guide member to facilitate its use as a handle and guide.

Another object of the invention is to provide in a linkage jack having a handle and guide member pivotally mounted on the jack linkage, stop members which will limit the movement of the handle and guide member to a short are when the jack is lowered and permit movement through a longer arc when the jack is raised.

These and other objects of the invention will be made apparent from the following drawings and description.

Figure 1 shows a partial elevation of the jack in partial section.

Figure 2 shows a perspective view of the handle and guide.

Figure 3 is a section on the line 3-3 of Figure 2.

Figure 4 is a partial plan of the ball nut and screw assembly with parts in section.

Figure 5 is a partial elevation of the ball nut and screw assembly with parts in section.

Figure 6 is a section on the line 6-6 of Figure 4.

Figure 7 is a partial sectional view similar to Figure 6 of a modification.

The scissors jack, which has a construction similar to the jack shown by Conrad in Patent 1,954,558, issued April 10, 1934, rests on a base plate 10 having upturned ends 12, so that the jack may be easily slid under a vehicle. A flange 14 is secured to the plate 10 at each side. The flanges 14 may be suitably welded adjacent each side of the plate 10 or may be the side 2,716,537 Patented Aug. 30, 1955 portions of a channel-shaped section which is welded to the plate 10. The upper plate or pressure pad 16 has side flanges 18 extending downwardly to provide attaching portions for the scissors links.- The side flanges 14 and 18 and the scissors links are thus elements of the linkage means of the jack. On each side of the jack a group of scissors links arranged in parallelogram shape provide support for the upper pad 16. A lower left link 20 is pivoted at its lower .end tothe right side of flange 14 and at the upper end to a pin 22 fixed on a collar 24. An upper left link 26 is pivoted at its lower end to the pin 22' and .at its upper end to the right end of flange 18. A lower right link 28 is pivoted at the lower end to the left side of the fiange 14 and at its upper end to a pin 30 on a collar 32. An upper right link 34 is pivoted at the lower end to the pin 30 and at the upper end to the left side of flange 18. This linkage is stabilized by the lower stabilizing link 36 which is pivoted at its upper end to the pin 30 and at. its lower end to the lower left link 20 adjacent its pivot to the flange 14. Similarly an upper stabilizing link 38 is pivoted at its lower end to the pin 22 and at the upper end to the upper right link 34 adjacent its pivot to the flange 18.

An elongated screw 42 is positioned in the collars 24 and 32. The screw has a suitable head portion consisting of the shoulder 44 which engages the collar 24 and a socket 46 with slots 48 to receive a conventional jack handle 50 employed to rotate the screw. At the other end of the screw a ball nut 52 is threaded on the screw and secured to the collar 32. The securing means consists of a strap 54 secured to the collar 32 by suitable means, such as screws or Welding; and having an aperture to receive a pin 56 in the base of the ball nut. The ball nut and collar assembly maybe made by first securing the strap 54 to the collar 32 with the apertured end portion bent to clear the pin 56. Then after the ball nut and pin 56 are assembled in the normal position the strap 54 with a suitable aperture therein is straightened over the pin 56. g

The foldable handle and guide consists ofa U-shaped portion 60 having an offset part 62 providing a hand grip and guide abutment for the handle and guide member at the base of the U. A sheet metal handle reinforcement 64 extends across the U-shaped portion immediately adjacent the offset part 62; and is secured to both legs of the U-shaped portion 60 by rolling the sheet metal around the rod-like legs. Each end of the U-shaped portion 60 is bent upward and outward to form a pintle 66 The inner portion of the handle and guide consists of a pair of support rods 70 having one end portion bent in a generally upward direction, and having at the end upwardly and outwardly extending pintles 72 which are positioned in apertures 74 in the flanges 18 in order to pivot the handle and guide element to the jack. The other ends of the support rods 70 are secured together by a sheet metal hinge brace 76 which has a central stiffening flange 78, and is secured to the rods 70 by rolling the ends around the rods as shown at 80 in Figure 3. Immediately adjacent the reinforcement 76 the rods 70 are looped at 82 to provide a hinge aperture to receive the pintle 66 of the U-shaped portion. The base portion of the hinge reinforcement 76 extends beneath loops 82 to provide a stopor seat 84 for the U-shaped portion. The rods 70 which are looped inwardly at 82 have an extension 86 extending upward to provide a bulbous end portion 88 spaced from the stop. 84 in order to provide a spring detent which will hold the U-shaped portion 60 against the stop 84. r i r Though a screw with a one-way brake and a ball nut this point.

parallel to the center line of the passage.

when the jack is in the collapsed position.

vehicle. "part 62 just engages the lower edge of the body the 'pad 16 engages the frame and on elevating the jack 'as shown in the copending-application of Kearful et al.

Serial No. 675,538, filed June 10, 1946, now Patent No. 2,609,178 granted September 2, 1952, may be used 'with this jack, it has been found that this simplified one-way ball nut makes it unnecessary to employ a oneway brake.

The one-way ball nut 52 is illustrated in detail in "Figures 4 to 7. The screw 42 has rounded thread 90,

while the nut 52'has an internal bore 92 with rounded internal thread 94 of the same pitch as thread 90. The matching threads provide a helical passage of circular cross section for the balls 96 between the screw and the nut. "fer passage portion is provided in the nut '52. At one Adjacent each end of this passage a transend the bore 98 enters the ball passage tangentially to provide the least resistance to the circulation of the balls. The transfer tube 100 has a leg extending into bore 98. The end'of this leg projects into the ball pas- At the other end The balls are guided into the leg end 104 of transfer tube 100 by a stop 106 secured in a bore in the nut 52 by suitable means, such as a press fit, set screws, threads, etc. A modified form of stop is shown in Figure 7 in which one side of the leg 110 of a similar transfer tube 112 is extended at 114 into the ball passage to provide a radial stop or abutment for the balls.

It will be noted that the stop 106 will allow the balls to pass slightly beyond the center line of the radial portion of the transfer tube. Thus the balls will positively lock and no circulation will occur in the direction in which the balls leave the helical groove at In the modification the abutment 114 is In this form the frictional forces are generally sufiicient to substantially or completely retard the circulation of the balls. If the abutment is bent toward the approaching balls 'to provide a short abutment portionmore nearly tangent to the screw the frictional retarding forces will be less and the balls will partially circulate.

The jackas generally used with automotive vehicles rests on the ground on the base plate 10 and is slid under the vehicle by holding and guiding with the offset part 62 employed as a hand grip. Since the downward movement of the handle and guide is limited by contact of brace 76 with the screw 42 and the upward movement of the handle is limited by contact with pad 16 as illustrated in Fig. 1, it is easier and more convenient to position the jack beneath a vehicle. With the handle and guide pivoted to pad 16 at one side of the jack and engaging the pad or screw 42 at the other 1 side of the jack, it will be readily seen that the jack may be more easily manipulated due to the fact that the swinging movement of the handle and guide is limited.

It is also a natural result of this structure that the swinging movement of the handle and guide is more limited The handle and guide member preferably has the proper length so that when the handle and guide rests on screw 42, and is substantially straight or unfolded, the offset part 62 at the free end engages the outer lower edge of the car body, fender or bumper, and the top or lifting pad 7 16 will be directly under the frame or other suitable part of the vehicle for applying a lifting force.

This jack is particularly adapted for lifting one side of a The guide is made so that when the offset one side and both the wheels are lifted. The jack is elevated by rotating the screw 42 by means of the handle 50, which is inserted in the socket 46, to draw the 4 ball nut 52 toward the screw head 44. Thus collars 24 and 32, which carry the pins 22 and 30 respectively, move together. The "intermediate lever ends pivoted on pins 22 and 30 located on both sides of the screw are then moved toward each other to lift the pad 16.

The reverse rotation of the screw 42 will allow the pivots 22 and 30 to spread apart and lower the top pad 16. When the jack is down the crank handle 50 is readily removed from the slot '48. The guide and handle 62 may then be folded on the pintle 66 so that the rod portions 70 are below pad 16, while the U- shaped portion 60 is above'the pad 16. Since the handle 62 extends beyond the end of the socket end of screw 42, this folding feature provides a compact jack for storage.

When a threaded screw and nut gear is employed on a scissors jack the friction 'in the gear holds the load in elevated position. However, when a ball nut is employed the friction in the gear -is not sufficient to hold the load elevated and the load force will rotate the screw to lower the load. Whenthe screw is rotated'to raise the load the balls circulate with a minimum of friction since they enter the helical passage through the radial bore 102 and leave through the tangential bore 93. However, when the load is lowered the balls either do not circulate or are retarded in their circulation since they enter the helical path in the nut through the tangential bore 98 but must leave through the radial bore 102. This increased friction between the screw and ball nut when it is rotated to lower the load 'holds the load in position but allows the load to be lowered with a minimum of effort applied to the screw.

The above described embodiments of the device illustrate the invention. Other modifications will be apparent to those versed in this field within the scope of the appended claims.

I claim:

1. A jack having a top pad and a bottom pad with facing inner sides, a linkage connected between said top and bottom pads, means to expandsaid linkage to raise said top pad, a guide and handle member having an inner portion pivoted to the inner side of one of said pads and extending between said pads, said member having an end portion pivoted to the inner 'portion beyond said pads and being foldable over the outer side of said one pad.

2. In a jack handle, a longitudinally extending member, said member having a loop adjacent one end to provide an aperture and a detent portion extending at an angle to said loop, a stop member secured to said longitudinal member on the side of said longitudinal member opposite said loop, a second longitudinal member having a laterally offset pintle pin portion pivotally mounted in said aperture, said second longitudinal member being movable past said detent portion and being releasably fixed against said stop member by said detent member.

3. In a jack, linkage means having a pair of spaced pads and connecting members connected between said pads to move said pads between a contracted and an expanded position, said linkage means also including a pair of spaced elements engaging said members and movable to extend said linkage'means to move said pads from said contracted to said expanded position, said linkage means also including operating means having a part engaging one element and having another part engaging the other element to move said elements to move said linkage means to move said pads from said contracted to said expanded position, a handle member pivoted for swinging movement to one of said pads, limit means on said handlemember to engage said linkage means to'lim'it movement of said handle member in one direction and to engage said linkage means to limit movement of said means limiting the pivotal movement of said memberto ing facing inner sides, a linkage having members connected between said pads to move said pads between ,a contracted and an expandedposition, saidlinkage including a pair of spaced elements engaging said members and movable to extend said linkage to move saidpads from said contracted tosaid expanded position, said'f linkage also including operating means having a part engaging one element and having another part engaging the other element to move said elements to move said linkage to move said pads from said contracted to said expanded position, a handle member pivoted for swinging movement in a longitudinal plane to one edge of the inner side of one of said pads and extending transversely toward the other edge of said one pad and between the inner side of said one pad and said linkage, limit means on said handle member to engage said one pad to limit movement of said handle member in one direction and,to engage said linkage to limit movement of said handle member in the other direction, and said limit means holding said handle in a substantially transverse position limiting the pivotal movement of said handle member to a short arc when said pads are in the contracted position and a long arc when said pads are in the expanded position. t

5. In a jack, a pair of longitudinally spaced pads having facing inner sides, a scissors linkageconnected-between said pads to move said pads between a contracted and an expanded position, a pair of transversely spaced elements engaging said linkage and movable to extend said linkage to move said pads from said contracted to said expanded position, said elements being located on transversely opposed sides of said pads and longitudinally between said pads, a screw and nut gear, said screw having a head engaging one element and extending transversely between said pads adjacent the other element and said nut engaging the other element to move said elements to move said linkage to move said pads from said contracted to said expanded position, a handle member pivoted for swinging movement in a longitudinal plane to one edge of the inner side of one of said pads and extending toward the edge of said one pad and between the inner side of said one pad and said screw, limit means on said handle member to engage said one pad to limit movement of said member in one direction and to engage said screw to limit movement of said member in the other direction, and said limit means limiting the pivotal movement of said member to a short are when said pads are in the contracted position and a long are when said pads are in the expanded position.

6. In a jack, a pair of longitudinally spaced pads having facing inner sides, a stabilized scissors linkage connected between said pads to move said pads between a contracted and an expanded position, a pair of transversely spaced elements engaging said linkage and movable to extend said linkage to move said pads from said contracted to said expanded position, said elements being located on transversely opposed sides of said pads and longitudinally between said pads, a screw and nut gear, said screw having a head engaging one element and extending transversely between said pads adjacent the other element and said nut engaging the other element to move said elements to move said linkage to move said pads from said contracted to said expanded position, a guide and handle member pivoted for swinging movement in a longitudinal plane to one edge of the inner side of one of said pads and extending toward the other edge of said one pad and between the inner side of said one pad and said screw, limit means on said guide and handle member to engage said one pad to limit movement of said member in one direction and to engage said screw to limit movement of said member in the other direction, and said limit means limiting the pivotal movement of said member to a short are when said pads are in the contracted position contracted and an expanded position, a pair of transversely spaced elements engaging said linkage and movable toward each other to extend-said linkage to move said pads from said contracted to said expanded position, said elements being located on transversely opposed sides of said pads and longitudinally between said pads, a screw and nut gear, said screw having a head engaging one element and extending transversely between said pads adjacent the other element and said nut engaging the other element to move said elements toward each other and through said linkage to move said pads from said contracted to said expanded position, atguide and handle member pivoted for swinging movement in a longitudinal plane to one edge of the inner side of one of said pads and extending toward the other edge of said one pad and between the inner side of said one pad and said screw, 'limit means on said guide and handle member to engage said one pad to limit movement of said member in one direction and to engage said screw to' limit movement of said member in the other direction, said limit means limiting the pivotal movement of said member to a short are when said pads are in the contracted position and a long are when said pads are in the expanded position, and said guide and handle member having hinge means intermediate its length to fold the end portion of said guide and handle member over the outer side of said one pad.

8. In a jack as defined in claim 7, said guide and handle member including a base portion pivoted to one edge of the inner side of said one of said pads and a handle portion extending transversely away from the jack, hinge means connecting said base portion and said handle portion for relative pivotal movement, and said hinge means being located'transversely beyond said one of said pads to permit said handle portion to be folded over the outer side of said one of said pads.

9. In a jack, linkage means having a pair of spaced pads and connecting members connected between said pads to move said pads between a contracted and an expanded position, said linkage means also including a pair of spaced elements engaging said members and movable to extend said linkage means to move said pads from said contracted to said expanded position, said linkage means also including operating means having a part engaging one element and having another part engaging the other element to move said elements on said linkage means to move said pads on said linkage means from said contracted to said expanded position, a handle member pivoted for swinging movement to the inside surface at one edge of one of said pads and extending transversely across said one pad, between said pair of spaced pads and beyond said pads, said handle member including a base portion pivoted to said one of said pads and a handle portion extending transversely away from said pads, hinge means connecting said base portion and said handle portion for relative pivotal movement, and said hinge means being located transversely beyond said one of said pads to permit said handle portion to be folded over the outside surface of said one of said pads.

10. A jack having a longitudinally spaced top pad and bottom pad, a stabilized scissors linkage connected to said top and bottom pads, a pair of elements on said linkage, a screw and nut gear, said screw having a head engaging one element, said nut engaging the other element, said nut and screw acting on said elements to raise said top pad, a guide and handle member pivoted to one of said pads for longitudinal pivotal movement and extending between said pads within the space defined by the perimeter of said pads, and means on said guide and handle member to be aligned with an external portion of the vehicle to locate said top pad beneath the portion of the vehicle to be contacted.

11; A jack having a top pad and a bottom pad spaced from each other, a. linkage connected between said top and bottom pads, means to expand said linkage to raise saidtop pad, 2. guide and handle member pivoted to one ofsaid pads and. extending between said pads and inter: engaging means on said one pad and said member to limit pivotal movement of said member in one direction and on said-means toexpand said linkage and said member to limit pivotal movement in the other direction.

12. A jack having a top pad and a bottom pad spaced from each other, elevating means connecting said top and bottom pads and movable between a contracted and an-expanded-position, actuating means to expandsaid' elevating means to elevate said top pad, a guide and handle member pivoted to, one of said pads adjacent one side and extending between said pads to the opposite side of said one of said pads and extending outward and upward and terminating in a handle and guide portion'and interengaging means on said member and said top pad and said actuating means to limit the pivotal movement of said member to a short are when said elevating means is .in contracted position and to limit the pivotal movement of said member to a long are when said elevating means is in the expanded position.

13. A jackhaving a top pad and a bottom pad, elevating means connecting said top and bottom pads, actuating means to expand. said elevatingmeans to elevate said top pad, a guide and handle member having a porand terminating in a hand. grip, portion, interengaging means between said 'memb'ehandsaid one pad and said actuating means to limit pivotal movement of saidf'member, said outwardly and. upwardly extending portion having a pivotedjoint, said joint'having a detent and stop.

means to normall'y maintain said handle and guide portion in extended position, ,and' said handle and guide,

portion being 'fol'dable over, said one pad.

References Citedin' the file of this patent UNITED.- STATES PATENTS- 1,5 18,627

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